From 3a4849acabd0352e420aaef40e351218e2b4dc46 Mon Sep 17 00:00:00 2001
From: tkrmagid <tkrmagid@git.tkrmagid.kr>
Date: Fri, 11 Sep 2026 23:02:35 +0900
Subject: [PATCH] =?UTF-8?q?perf(=EC=9E=AC=EC=83=9D=EC=A7=80=EC=97=B0):=20?=
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---
 bot/src/classes/LavalinkManager.ts | 16 +++++++++++
 bot/src/events/messageCreate.ts    |  2 ++
 resolver/ytresolver.py             | 46 ++++++++++++++++++++++++------
 3 files changed, 55 insertions(+), 9 deletions(-)

diff --git a/bot/src/classes/LavalinkManager.ts b/bot/src/classes/LavalinkManager.ts
index c7c32e1..1751315 100644
--- a/bot/src/classes/LavalinkManager.ts
+++ b/bot/src/classes/LavalinkManager.ts
@@ -76,6 +76,22 @@ export class LavalinkManager {
     return !!this.shoukaku.options.nodeResolver(this.shoukaku.nodes);
   }
 
+  /**
+   * 유튜브 URL을 음성 접속 전에 미리 ytresolver에 걸어둔다(fire-and-forget).
+   * 리졸버가 진행 중 요청을 합쳐주므로(coalescing), 음성 접속(~2초) 동안 리졸브(~2.5초)가
+   * 겹쳐 진행돼 실제 재생 시점엔 캐시 적중 → 첫 재생 지연이 크게 줄어든다.
+   * resolvePlayable이 쓰는 캐시 키(info.uri = https://www.youtube.com/watch?v=ID)와 맞추기 위해
+   * 표준 watch URL로 변환해 요청한다.
+   */
+  public prewarmYoutubeUrl(raw: string) {
+    try {
+      const m = raw.match(/(?:youtu\.be\/|[?&]v=|\/shorts\/|\/embed\/|\/live\/)([A-Za-z0-9_-]{11})/);
+      if (!m) return;
+      const canonical = `https://www.youtube.com/watch?v=${m[1]}`;
+      fetch(`${Config.ytresolverUrl}/resolve?url=${encodeURIComponent(canonical)}`, { signal: AbortSignal.timeout(45000) }).catch(() => {});
+    } catch { /* prewarm 실패는 무시 (실제 재생 시 정상 경로로 리졸브) */ }
+  }
+
   getPlayer(guildId: string) {
     return this.players.get(guildId);
   }
diff --git a/bot/src/events/messageCreate.ts b/bot/src/events/messageCreate.ts
index 268b3a2..8be6973 100644
--- a/bot/src/events/messageCreate.ts
+++ b/bot/src/events/messageCreate.ts
@@ -51,6 +51,8 @@ async function handleMessage(message: Message): Promise<void> {
   const gdb = DB.guild.get(message.guild.id);
   if (!gdb?.channel_id) return;
   if (gdb.channel_id !== message.channel.id) return;
+  // 유튜브 URL이면 음성 접속 전에 미리 리졸브를 걸어 첫 재생 지연을 줄인다(리졸버가 진행분을 합쳐줌).
+  lavalinkManager.prewarmYoutubeUrl(message.content);
   let player = lavalinkManager.getPlayer(message.guild.id);
   const voiceChannel = getVoiceChannel(message.member);
   if (!player) {
diff --git a/resolver/ytresolver.py b/resolver/ytresolver.py
index 727ec5a..d6845a9 100644
--- a/resolver/ytresolver.py
+++ b/resolver/ytresolver.py
@@ -27,6 +27,7 @@ YTDLP = os.environ.get("YTDLP", "/usr/local/bin/yt-dlp")
 COOKIE_FILE = os.environ.get("YTRESOLVER_COOKIE", "/root/bot/db/ytcookie.txt")
 PORT = int(os.environ.get("YTRESOLVER_PORT", "8779"))
 CACHE = {}
+INFLIGHT = {}      # target -> {"event": Event, "url": str|None}  진행 중 리졸브 합치기(coalescing)
 LOCK = threading.Lock()
 TTL = 1800  # 리졸브된 URL 캐시 30분(googlevideo URL 자체는 약 6시간 유효)
 
@@ -53,12 +54,7 @@ def first_url(out):
     return lines[0] if lines else None
 
 
-def resolve(target):
-    now = time.time()
-    with LOCK:
-        hit = CACHE.get(target)
-        if hit and hit[1] > now:
-            return hit[0]
+def _do_resolve(target):
     try:
         out = run_ytdlp(target, use_cookies=False)
         url = first_url(out)
@@ -69,13 +65,45 @@ def resolve(target):
     except subprocess.TimeoutExpired:
         print("[result] TIMEOUT", file=sys.stderr, flush=True)
         return None
-    ok = bool(url and url.startswith("http"))
-    if not ok:
+    if not (url and url.startswith("http")):
         print(f"[result] FAIL {(out.stderr or out.stdout or '')[:240]}", file=sys.stderr, flush=True)
         return None
     print(f"[result] OK {url[:60]}", file=sys.stderr, flush=True)
     with LOCK:
-        CACHE[target] = (url, now + TTL)
+        CACHE[target] = (url, time.time() + TTL)
+    return url
+
+
+def resolve(target):
+    now = time.time()
+    with LOCK:
+        hit = CACHE.get(target)
+        if hit and hit[1] > now:
+            return hit[0]
+        # 같은 target이 이미 리졸브 중이면, 새 yt-dlp를 띄우지 않고 그 결과를 기다린다.
+        # (봇이 음성 접속과 동시에 미리 리졸브를 걸어두면, 실제 재생 요청이 이 진행분에 합쳐져
+        #  음성 접속 시간과 리졸브 시간이 겹쳐 첫 재생 지연이 크게 줄어든다.)
+        entry = INFLIGHT.get(target)
+        owner = entry is None
+        if owner:
+            entry = {"event": threading.Event(), "url": None}
+            INFLIGHT[target] = entry
+    if not owner:
+        entry["event"].wait(50)
+        with LOCK:
+            hit = CACHE.get(target)
+        return hit[0] if hit and hit[1] > time.time() else entry.get("url")
+    # owner: 실제 리졸브 수행
+    url = None
+    try:
+        url = _do_resolve(target)
+    except Exception as e:
+        print(f"[result] ERR {str(e)[:120]}", file=sys.stderr, flush=True)
+    finally:
+        entry["url"] = url
+        with LOCK:
+            INFLIGHT.pop(target, None)
+        entry["event"].set()
     return url